Tesla Powerwall › Problems
Powerwall output throttled or cut to half of what it should deliver
The Powerwalls deliver much less power than they should for how many there are, often about half, or throttle down after a few minutes. This page covers what the lights and messages mean, what to check first, and the causes behind it.
What the lights mean
| What you see | What it means |
|---|---|
| Powerwall 2 light off | The Powerwall is not enabled or is switched off. |
| Powerwall 2 light flashing, or a Powerwall+ light blinking once every 4 seconds | The Powerwall is on but is not communicating with the gateway. |
| Backup Switch light flashing | The Backup Switch has power but is not communicating with the Powerwall. |
| Powerwall 2 light solid | The Powerwall is enabled and communicating with the gateway. |
| Powerwall 2 light pulsing | The Powerwall is enabled and charging or discharging. |
| Powerwall 3 logo solid white | Normal operation. |
| Powerwall 3 logo flashing white | Idle; the owner manual says it will go to sleep if nothing is in progress. |
Error codes that go with this problem
| Code | What it means |
|---|---|
| Unable to start system: sitemaster needs a default real mode | Shown when Start System is pressed in the app. The Powerwall can't start because the inverters, gateway and Powerwalls were never commissioned together. |
What to check first
- Check that every Powerwall's breaker is on. A Powerwall breaker that was off or tripped has capped charging and halved the power with no error shown, and switching it back on brought full power back.
- Look at the light on each Powerwall and compare it with the table above.
- Note how the power drops: whether a unit holds 5 kW for only a few minutes and then falls to about 1 kW, or charging slows past about 90%, and whether the fan runs at high speed.
- If the app is stuck on the Network Setup screen and nothing is producing, do a full power cycle at the breakers.
- If a breaker in the panel fitted with the system trips whenever two loads run together, leave it off until the wiring is checked.
- If the power stays low, it needs a technician. Ask your installer to finish commissioning the system, or ask Tesla to commission it remotely.
Safety. If a breaker in the new panel keeps tripping, leave it off until the wiring has been checked, so a dangerous miswiring or fire risk can be ruled out first.
The causes and the fixes
Partners see the causes behind this problem, most common first, the checks that tell them apart, and the fix for each, with part numbers and recent prices when a part is involved.